Refrigeration



Patented Sept. 21, 1943 REFRIGERATION 1 7 Albert R. Thomas, Evansville, Ind., assignor to Servel, Inc., New York, N. Y.,

Delaware a corporation of Application January 4, 1940, Serial No. 312,315 '1 Claims. (01. 62-1195) My invention relates to refrigeration, and more particularly to refrigeration systems making use of evaporation of refrigerant fluid in the presence of an auxiliary inert fluid. 7 It is an object of the invention to provide a refrigeration system of this type having high efflciency during usual operation and having in.- I

creasing capacity under high load conditions.

The drawing shows more -or less diagrammatically a refrigeration system embodying the invention. In this system, a generator includes a coil l and a vessel The bottom of vessel H is connected to the lower end of coil Ill. The lower end of coil I0 is connected to a surge chamber I2, and the latter is connected by a conduit, I3

I to the bottom of vessel II. The upper end of coil I0 is connected by a conduit M to a gas and liquid separating vessel l5. The upper part of vessel I5 is connected to the top of generator vessel H by a conduit l6.

An absorber H is shown as a vessel provided a with liquid spreading bafile plates I8. The bottom of the absorber I! has an opening l9 surrounded by an upstanding ledge 20. Below the absorber is a vessel 2|. The top of vessel 2| communicates with the absorber I! through opening,

i9. The bottom of vessel 2| is connected by a conduit 22 to the generator vessel I l.

The bottom of absorber i1 is connected to a conduit 23 which is located concentrically around a tube 24, and also concentrically within a tube 25. The pipes 23, 24, and 25 form-a three-passage heat exchanger and are formed into a coil. The other end of conduit 23 is closed. At the top of the closed end of conduit 23 is a small opening or orifice 26. The inner tube 24 is contor 32 is located in a refrigerator storage compartment 33. The upper end of evaporator 32 is connected by a conduit 34, a gas heat exchanger 35; and a conduit 36 to the upper part of vessel 2|. The lower end of evaporator 32 is connected by a conduit 31, gas heat exchanger 35, and a conduit 38 to the top of absorber l1.

' tern will The outlet end of condenser 30 is connected by j a conduit 39 to a vessel 40. The other end of vessel 40 is connected by a conduit 4| to the circuit which includes evaporator 32.

The generator coil l0 and vessel II are heated by any suitable means such as a gas burner 42. Condenser 30 is provided with fins for air cooling, but, as known, may be cooled by water or intermediate heat transfer system. Absorber I1 isprovided with fins for air cooling but, as known, may be water cooled or cooled by an intermediate heat transfer system. I

The system is hermetically sealed and contains a refrigerant fluid, an absorbent therefor, and an auxiliary inert fluid. Ammonia, water, and

hydrogen may be used. The ammonia and water are introduced as a solution, and the hydrogen is introduced before sealing of the system and at a pressure such that the total pressure in the sysbe the condensing temperature of ammonia at a high room temperature.

In operation, burner 42 is lighted. Heat from the burner heats solution in coil I0 and, at a Heating of the lower temperature, in vessel M. solution causes expulsion of ammonia vapor. Vapor formed in coil and through conduit I4 into separating vessel l5. The gas becomes trapped in liquid in coll Ill and conduit l4 so that a rising column'of gas and liquid extends upward through conduit I4 and overflows the upper end of this conduit into vessel l5.

Vapor expelled from solution in vessel rises through the liquid in this vessel. Vapor from p vessel l5 flows through conduit l6 and joins vapor in the upper part of vessel Vapor in the upper part of Vessel bubbles through liquid in the outer heat exchanger conduit 25. The level of liquid in conduit 25 is the same as the level in vessel 2| and should be about at the small opening 26 in triple heat exchanger. conduit 23.

Vapor leaving the surface level of liquid in pipe.

25 flows on upward through this pipe in heat exchange relation with pipe 23. The vapor flows from the upper end of pipe 25 through conduit 29 to condenser 30. Vapor condenses to liquid incondenser 30. Liquid flows through conduit 3| into the upper part of evaporator 32.

Liquid flows downward in evaporator 32 in the presence of hydrogen. The liquid evaporates and difiuses into the hydrogen, producing a re? frigerating effect for cooling compartment 33.v

The resulting mixtureof ammonia vapor and hydrogen gas flows from the upper end of evaporator 32 through conduit 34, gas heat exchanger 35, and conduit 36 to vessel 2|. This gas and vapor mixture, calledstrong or rich |0 rises through the coil made within the scope of the invention which 2 2,329,863 gats, flaws 1through vessel 2|, through opening I9. is limited only as indicated in the following in o a sor er claims. Ammonia vapor is absorbed by weak solution What isclaimedis: which flows downward in the absorber over plates 1. An absorption refrigeration system having l8- The hy r n. or weak or poor g flows 5 an evaporator and an absorber connected in a fr the p r p r a o er through 0011-- circuit for inert gas, a generator, a first conduit ui 8 h at exchanger 35, and conduit 31 to for conducting weak absorption liquid from said the lower end of evaporator 1". generator to said absorber, a second conduit for weakened solution flows from separator I conducting strong absorption liquid from said through conduit 28, imer heat exchanger con- 10 absorber to said generator, the strong absorptig; duit 24. and conduit 1, into the upper part of liquid flowing by gravity in said second cond absorber I! from whence it flows downward over and having two surface levels at different eleva plates Is to absorb the ammonia. Enricthed abtlons, a third conduit11 ftgr condgfgilngt gengrator sorption liquid flows from the lower par of abvapor, said three cond being ea exc ange sorber l1 into conduit 23. The enriched liquid relation at a level intermediate said liquid surflows out of conduit 23 at the lower end through face levels. and a liquid holder so connected in opening 28 into the lower end of conduit 25. said gas circuit as to hold a substantially stags e 4 erv s 1 n in as which is mostly nant quantity of absorption liquid at a level beilsiiydrogen. lginderdabnormglily high load condiilzowt theuilipper (g svaiid sifirface legals and in cor;

ons, uncon ense ammo a vapor rom conac w gas 0 ng rom sa evapora or denser 30 displaces hydrogen from vessel 40 said absorber. through conduit ll into the evaporator-absorber 2. An absorption refrigeration system having gas circuit so that refrigeration will continue at an evaporator and an absorber in a circuit for a higher total pressure in the system. inert gas, a generator, structure including a con- In gas heat exchanger 35 heat is conserved duit providing a path of flow for absorption liq- I between gas flowing to and from the low temuid from said absorber toward said generator, perature evaporator with respect to the higher and a holder so connected in said gas circuit temperature absorber. In conduits 23 and 24 of as to hold a substantially stagnant quantity of the triple heat exchanger, heat is conserved b2; gefrigerant absolit'ibent in itzhe t greselrce bot bgas tween the strong and weak solution flowing owing from sa evapora or sa a sor er. and from the absorber with respect to the higher the level of the top of said absorbent quantity temperature generator. The cross-sectional area being vertically spaced from the uppermost surgf conduiii: 23 around ctanduit 24, Cand tlcifi size of gace igve'l 13f liquid ti: said path of flow of liquid ow restr ctor opening 6 are ma e so at conowar sa genera r. duit 23 will be substantially flooded at the rate 3. An absorption refrigeration system having atv which liquid is usually caused to circulate by an evaporator and an absorber in a circuit for the vapor lift. inert gas, a generator connected with said ab- Vapor which flows by bubbling through liquid sorber in a circuit for absorption liquid, and a in thelylower endthof healt exchlanger conduit 25 stoizgeichamber for iabsorption liiqlllllld s: coriiis ana zed. In e ana yzer t evapor and en- 40 nec d n said gas crcut that lq d heren riched solution tend to reach equilibrium. Vapor contacts gas flowing from said evaporator to said flowing from the analyzer through the upper part absorber and so connected to said liquid circuit of heat exchanger conduit 25 is rectified. The that liquid in the vessel is substantially stagnant vapor is cooled by heat transfer to strong soluand has a surface level vertically spaced from tion in conduit 23, causing condensation of water the uppermost surface level of liquid in that part vapor. The condensate flows bac down through of said liquid circuit in which liquid is flowing conduit 25 and joins strong solution in the lower toward said generator. part of this conduit flowing to the generator. 4. An absorption refrigeration system having Conduit 22 which connects vessel 2| to generaan absorber connected in both a circuit for prestor vessel H is a small diameter tube. This tube sure equalizing fluid and a circuit for absorption and vessel 2| form a dead-end passage for liquid. quid. a gen a i Said absorption liquid When the rate of evaporation of ammonia in cult, a liquid flow restriction in that part of said gvaporator 32 is 131w, athe gas which enters vessel iiqllgd circuit in which liquid flows from said ab- I through cond t 8 contains ammonia at a sor or downward toward said enera-tor, such .low partial pressure. Thereupon ammonia evapflow restriction causing liquid flowing toward orates from solution in vessel 2|, tending to reach said generator to have two vertically spaced liqequilibrium with the gas. This causes an inuid surface levels, a conduit for generator vapor creatsgtirihtheiansfimt (g1 atmfionlg if; the alctgltl e in great exchange with said liquid between said par 0 e crc so a e e cency o r e sur ace leve s, and a conduit forming part of system working with a stronger solution in the said liquid circuit for conducting absorption liqactive part is increased. Under extreme load uid flowing from said generator toward said conditons, tgas entering vessel 2| through conabsorber in heat exchange with absorption liquid duit 3 cm 8111s amnmma "5Por at a high flowing towardsaid generator between said surtial pressure so that ammonia vapor is absorbed facelevels ut of the gas in the solution invessel 2|. This 05 5. An absorption refrigeration system havingv reduces the average concentration of solution an ab sorber,.a generator, and structure whereby in the active part of the system so that, as known, b v

. a sorption liquid flows from said absorber downthe capacity of the system is increased. This d condition is maintained due to the fact that ggf gg i gsig 3 m in fi g in vessel'2| is de r ui n- 8 an pper q sur ace cemed n 5 3, 3 a f g i i 2? level and a lower liquid surface level, said structhrough the small pipe 22 to the generator vessel tule u nii a tube forming a part of said M in the active part of the circuit, P h f flow at a region below said lower surface Various changes and modifications may be vel and also providin a passage for conducting generator vapor in heat exchange relation. and

out of physical contact with liquid in said path of flow at' a region between said surface levels.

6. An absorption refrigeration system havingan absorber, a generator, and structure whereby absorption liquid flows from said absorber to-.

ward said generator in a path of flow in which the liquid has an upper liquid surface level and a lower liquid surface level, said structure including a plurality of conduits one within another, one of said conduits forming a part of conveying generator vapors between said liquid 15 surface levels.

7. An absorption refrigeration system having an absorber, a generator. and structure whereby absorption liquid flows from said absorber toward said generator in a path of flow in which the 5 liquid has an upper liquid'surface level and a lower liquid surface level, said structure including a pipe forming a part of said path of flow below said lower liquid surface level through which generator vapor also flows in contact with 10 liquid, said pipe also providing a passage for generator vapor flowing-out of physical contact but in heat transfer relation with liquid between said liquid surface levels.

ALBERT a. THOMAS. 

